[BC] IBOC AM Quality

[padrino]

Broadcasters' Mailing List <broadcast at radiolists.net> writes:
>>All of that being said, however, if you feed quality audio in, and 
>>process carefully - by which I mean keeping the sound open, not 
>>dense, and being careful about how you handle the high bands - AM 
>>IBOC can sound quite nice.
>
>
>You have to have a continual supply of very good weed to believe the 
>same grunge processing won't be used on the digital signals. It has 
>to be. Otherwise the constant mode switching in cars will drive the 
>listener nuts. Bad processing habits are very hard to break. The 
>minute the General Manager hears his signal softer than the 
>competition the order will go out to make it loud.

No amounts of 'whacky-tobacky' needed. :)

Processing for lower bitrates requires that the audio processing is NOT
what we've come to know. Research has shown that low bitrate codecs DO NOT
like clipping...NOR...limiting that contains high levels of
intermodulation distortion (IMD). Most dynamic peak limiters exhibit high
IMD and this causes added 'artifacting' in the coder. Just spent a good
year working on this, and the proof is in the processing algorithms.

Processing for HD does allow level normalization that eliminates
discrepancies when the receiver switches back-n-forth.

-Frank Foti